diff options
| author | Teng Qin <qinteng@fb.com> | 2017-04-24 19:00:37 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-04-25 11:57:45 -0400 |
| commit | 8fe45924387be6b5c1be59a7eb330790c61d5d10 (patch) | |
| tree | 1879f4fd4d14907155b1ebb2fd85ff26aa89ebbe /include | |
| parent | 472ecf084a7687347f79720c83881c07407bfd8b (diff) | |
| download | linux-8fe45924387be6b5c1be59a7eb330790c61d5d10.tar.gz linux-8fe45924387be6b5c1be59a7eb330790c61d5d10.tar.bz2 linux-8fe45924387be6b5c1be59a7eb330790c61d5d10.zip | |
bpf: map_get_next_key to return first key on NULL
When iterating through a map, we need to find a key that does not exist
in the map so map_get_next_key will give us the first key of the map.
This often requires a lot of guessing in production systems.
This patch makes map_get_next_key return the first key when the key
pointer in the parameter is NULL.
Signed-off-by: Teng Qin <qinteng@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/trace/events/bpf.h | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/include/trace/events/bpf.h b/include/trace/events/bpf.h index c3a53fd47ff1..52c8425d144b 100644 --- a/include/trace/events/bpf.h +++ b/include/trace/events/bpf.h @@ -321,11 +321,14 @@ TRACE_EVENT(bpf_map_next_key, __dynamic_array(u8, key, map->key_size) __dynamic_array(u8, nxt, map->key_size) __field(bool, key_trunc) + __field(bool, key_null) __field(int, ufd) ), TP_fast_assign( - memcpy(__get_dynamic_array(key), key, map->key_size); + if (key) + memcpy(__get_dynamic_array(key), key, map->key_size); + __entry->key_null = !key; memcpy(__get_dynamic_array(nxt), key_next, map->key_size); __entry->type = map->map_type; __entry->key_len = min(map->key_size, 16U); @@ -336,8 +339,9 @@ TRACE_EVENT(bpf_map_next_key, TP_printk("map type=%s ufd=%d key=[%s%s] next=[%s%s]", __print_symbolic(__entry->type, __MAP_TYPE_SYM_TAB), __entry->ufd, - __print_hex(__get_dynamic_array(key), __entry->key_len), - __entry->key_trunc ? " ..." : "", + __entry->key_null ? "NULL" : __print_hex(__get_dynamic_array(key), + __entry->key_len), + __entry->key_trunc && !__entry->key_null ? " ..." : "", __print_hex(__get_dynamic_array(nxt), __entry->key_len), __entry->key_trunc ? " ..." : "") ); |